Apparatus and processes for forming thermoplastic materials into solid products having three dimensional (3-D) surface patterns and shapes are disclosed in U.S. Pat. Nos. 4,128,369; 4,290,248; 5,167,781; 5,244,618; 5,330,341; 5,458,477; 5,505,599; and 5,700,495. All the products disclosed in these foregoing patents are solid. The present invention enables continuous production from heated thermoplastic polymeric materials hollow products having attractive, three-dimensional (3-D) surface patterns and profile shapes to provide products having a unique design. The patterns may be random or repetitious.